An optimization mathematical model of the pile forces for piled breasting dolphins in the open sea under various loading conditions is presented. The optimum layout with the well distributed pile forces and the least ...An optimization mathematical model of the pile forces for piled breasting dolphins in the open sea under various loading conditions is presented. The optimum layout with the well distributed pile forces and the least number of piles is achieved by the multiplier penalty function method. Several engineering cases have been calculated and compared with the result of the conventional design method. It is shown that the number of piles can be reduced at least by 10%～20% and the piles' bearing state is improved greatly.展开更多
The goal of the modern farming systems is to economize energy consumption and to reduce farming costs.Proper selection and use of agricultural machines are important factors to achieve this end.Rotary tillers are till...The goal of the modern farming systems is to economize energy consumption and to reduce farming costs.Proper selection and use of agricultural machines are important factors to achieve this end.Rotary tillers are tillage tools that are used for accomplishment of both the primary and secondary tillage practices.Considering the widespread application of rotary tillers and wide use of modern tractors in Iran,optimal design of these machines is mandatory.Therefore in this study,the optimal working width and optimal diameter of the rotary tiller's rotor proportionate with the power of the MF 399 tractor was delineated based on the energy method.This theoretical method is based on the specific works of tractor and rotary tiller.Results showed that the optimal working width and optimal diameter of the rotary tiller’s rotor with maximum of forward speed 1 m/s for tractor was 240 cm and 6.27 cm,respectively.展开更多
Simultaneous optimization of refrigeration system(RS)and its heat exchanger network(HEN)leads to a large-scale non-convex mixed-integer non-linear programming(MINLP)problem.Conventionally,researchers usually adopted s...Simultaneous optimization of refrigeration system(RS)and its heat exchanger network(HEN)leads to a large-scale non-convex mixed-integer non-linear programming(MINLP)problem.Conventionally,researchers usually adopted simplifications to confine problem scale from being too large at the cost of reducing solution space.This study established an optimization framework for the simultaneous optimization of RS and HEN.Firstly,A more comprehensive and compact model was developed to guarantee a relatively complete solution space while reducing model scale as well as its solving difficulty.In this model,a tandem arrangement of connecting sub-coolers and expansion valves was considered in the superstructure;and the pressure/temperature levels were optimized as continuous variables.On this basis,we proposed a"two-step transformation method"to equivalently transform the cross-level structure into a no n-cross-level structu re,and the de-redundant superstructu re was established with ensuring comprehensiveness and rigor.Furthermore,the MINLP model was developed and solved by Particle Swarm Optimization algorithm.Finally,our methodology was validated to get better optimal results with less CPU time in two case studies,an ethylene RS in an existing plant and a reported propylene RS.展开更多
Rotary tool of garbage crusher is the key component of the whole mechanism, which is of vital importance to tool design and analysis. Based on ANSYS Workbench 3D modeling, we carried on finite element analysis to tool...Rotary tool of garbage crusher is the key component of the whole mechanism, which is of vital importance to tool design and analysis. Based on ANSYS Workbench 3D modeling, we carried on finite element analysis to tool, and used the method of goal driven optimization to optimize the rotary tool. The optimization proves that the optimized maximum equivalent stress is 544.14 MPa, the quality is less, and the optimized rotary tool size is more reasonable. So it provided reasonable and scientific reference frame to the structural design of rotary tool.展开更多
Cascade refrigeration system(CRS)can meet a wider range of refrigeration temperature requirements and is more energy efficient than single-refrigerant refrigeration system,making it more widely used in low-temperature...Cascade refrigeration system(CRS)can meet a wider range of refrigeration temperature requirements and is more energy efficient than single-refrigerant refrigeration system,making it more widely used in low-temperature industry processes.The synthesis of a CRS with simultaneous consideration of heat integration between refrigerant and process streams is challenging but promising for significant cost saving and reduction of carbon emission.This study presented a stochastic optimization method for the synthesis of CRS.An MINLP model was formulated based on the superstructure developed for the CRS,and an optimization framework was proposed,where simulated annealing algorithm was used to evolve the numbers of pressure/temperature levels for all sub-refrigeration systems,and particle swarm optimization algorithm was employed to optimize the continuous variables.The effectiveness of the proposed methodology was verified by a case study of CRS optimization in an ethylene plant with 21.89%the total annual cost saving.展开更多
基金TheworkwassupportedbytheNationalFoundationofHighPerformanceComputation (No .9810 0 5 )
文摘An optimization mathematical model of the pile forces for piled breasting dolphins in the open sea under various loading conditions is presented. The optimum layout with the well distributed pile forces and the least number of piles is achieved by the multiplier penalty function method. Several engineering cases have been calculated and compared with the result of the conventional design method. It is shown that the number of piles can be reduced at least by 10%～20% and the piles' bearing state is improved greatly.
文摘The goal of the modern farming systems is to economize energy consumption and to reduce farming costs.Proper selection and use of agricultural machines are important factors to achieve this end.Rotary tillers are tillage tools that are used for accomplishment of both the primary and secondary tillage practices.Considering the widespread application of rotary tillers and wide use of modern tractors in Iran,optimal design of these machines is mandatory.Therefore in this study,the optimal working width and optimal diameter of the rotary tiller's rotor proportionate with the power of the MF 399 tractor was delineated based on the energy method.This theoretical method is based on the specific works of tractor and rotary tiller.Results showed that the optimal working width and optimal diameter of the rotary tiller’s rotor with maximum of forward speed 1 m/s for tractor was 240 cm and 6.27 cm,respectively.
基金supported by the National Natural Science Foundation of China(21978203)the Natural Science Foundation of Tianjin(19JCYBJC20300)。
文摘Simultaneous optimization of refrigeration system(RS)and its heat exchanger network(HEN)leads to a large-scale non-convex mixed-integer non-linear programming(MINLP)problem.Conventionally,researchers usually adopted simplifications to confine problem scale from being too large at the cost of reducing solution space.This study established an optimization framework for the simultaneous optimization of RS and HEN.Firstly,A more comprehensive and compact model was developed to guarantee a relatively complete solution space while reducing model scale as well as its solving difficulty.In this model,a tandem arrangement of connecting sub-coolers and expansion valves was considered in the superstructure;and the pressure/temperature levels were optimized as continuous variables.On this basis,we proposed a"two-step transformation method"to equivalently transform the cross-level structure into a no n-cross-level structu re,and the de-redundant superstructu re was established with ensuring comprehensiveness and rigor.Furthermore,the MINLP model was developed and solved by Particle Swarm Optimization algorithm.Finally,our methodology was validated to get better optimal results with less CPU time in two case studies,an ethylene RS in an existing plant and a reported propylene RS.
文摘Rotary tool of garbage crusher is the key component of the whole mechanism, which is of vital importance to tool design and analysis. Based on ANSYS Workbench 3D modeling, we carried on finite element analysis to tool, and used the method of goal driven optimization to optimize the rotary tool. The optimization proves that the optimized maximum equivalent stress is 544.14 MPa, the quality is less, and the optimized rotary tool size is more reasonable. So it provided reasonable and scientific reference frame to the structural design of rotary tool.
基金supported by the National Natural Science Foundation of China(21978203)the Natural Science Foundation of Tianjin City(19JCYBJC20300)。
文摘Cascade refrigeration system(CRS)can meet a wider range of refrigeration temperature requirements and is more energy efficient than single-refrigerant refrigeration system,making it more widely used in low-temperature industry processes.The synthesis of a CRS with simultaneous consideration of heat integration between refrigerant and process streams is challenging but promising for significant cost saving and reduction of carbon emission.This study presented a stochastic optimization method for the synthesis of CRS.An MINLP model was formulated based on the superstructure developed for the CRS,and an optimization framework was proposed,where simulated annealing algorithm was used to evolve the numbers of pressure/temperature levels for all sub-refrigeration systems,and particle swarm optimization algorithm was employed to optimize the continuous variables.The effectiveness of the proposed methodology was verified by a case study of CRS optimization in an ethylene plant with 21.89%the total annual cost saving.
